1. Field of the Invention
The present invention relates to an ink tube for an ink jet printer. More particularly, the present invention relates to an ink tube that is used to discard waste ink to the outside of an ink head, when the ink head of the ink jet printer is cleaned and used to supply ink from an ink tank to the ink head.
2. Description of the Related Art
In the ink jet printer, the ink head is connected with the ink tube necessary for feeding the ink. The ink tube is used to discard the waste ink to the outside of the ink head, when the ink head of the ink jet printer is cleaned and used to supply the ink from the ink tank to the ink head.
The liquid ink printer using the ink tube disclosed in Japanese Patent Application Laid-Open No. 10-29317 has a liquid ink printing head and an ink circulation device.
To discharge the ink from the ink tube, the ink tube is squeezed. Thus the ink tube is demanded to return to its original state when it is pressed and deformed. That is, the ink tube is demanded to be flexible. In dependence on a construction inside the printer, it is necessary to dispose the ink tube by bending it along other members. Thus if the ink tube has a low degree of flexibility, the ink does not flow smoothly. Thus it is conventional to make the ink tube of vulcanized silicone rubber, fluorine rubber, EPDM or the like capable of realizing rubberlike elasticity.
The ink tube is also demanded to have low water vapor permeability and air permeability. That is, when the ink tube has a low water vapor permeability, vaporized water of the ink inside the ink tube does not permeate the ink tube. Thereby the ink can be prevented from being set. Thus it is possible to allow the ink tube to keep its performance for a long time. If the ink tube has a low air permeability, oxygen or the like present outside the ink tube does not permeate the ink tube. Thus it is possible to prevent the ink inside the ink tube from being deteriorated by oxidization.
It is difficult to allow the ink tube made of the vulcanized rubber to have low water vapor permeability and air permeability and at the same time a high degree of flexibility. The ink tube made of the vulcanized rubber is also demanded to have high processability and productivity to reduce the cost for producing it.